Ok, I'm Stumped

[DVS JEZ]

That orange is consistant with fuel octane booster. Have u ever ran it?

[zebra]

Not since I have owned the car

Though I did fill up with caltex gold about a week ago. Not sure if that is relevant though

[DVS JEZ]

Whats caltex gold?

How long have u had the car? Octane booster stays in the system for while.

[zebra]

Some sort of premium unleaded. Was the only choice I had where I was.

Only had the car a week and a bit lol

[GTRNUR]

My money is on that the rings aren't broken, but the ring land for the top ring has failed. Listening for where you can hear compressed air escaping from most when doing the leak down test will give you more clues. Sump, head, intake exhaust. If you hear anything in the intake or exhaust, its valves/seats. You shouldnt hear anything (or very little). If its either of the other two, combined with a bad result and its a head off/engine out deal looking for bad valves and seats, or a broken piston/rings.

Stem seal leaks will only have an effect on the cylinder when a valve is open, and have no effect at all on cylinder compression.

[zebra]

This is why I'm confused, you would think that a broken ring land would show up with oil on the plug and piston crown, as well as it blowing smoke under load.

It has none, it is also very quiet as I said before.

If I wasnt so poor due to it being the silly season I would've pulled the engine already, but alas I am broke, hence this thread lol

The lack of oil in the chamber tells me if it is guides/seals, than it is the exhaust side

[GTRNUR]

I agree with you, but look at the JZ piston designs. They run a massive crown thickness above the top ring. If the 2nd ring and oil rings are intact then you won't get oil above the piston crown and in the combustion chamber.

[zebra]

this is true, didnt think of it that way.

[tridentt150v]

old rule - If it smokes after idling its valve related, if it smokes when you accelerate its rings. You say it smokes at idle and then you rev it. This means valves, guides etc. But on a turbo car you have to add the turbo seal.

[zebra]

Yeah, 100% agree,

Was just more bemused by the lack of comp on 1 cylinder.

Leak down test will reveal all I guess

[DVS JEZ]

Did u try a wet test?

I bet the last owner used octane booster when he was running 2 bar the day before he sold it to u .... Well hopefully not. But he must have used booster for the plugs to look like that

[zebra]

nah no wet test yet.

lol 2Bar with standard turbos would prob make less power than it does standard

[Gerg_R31]

Im still leaning towards firing ring failure on head gasket for low comp

and how does the piston top look compared to the other cylinders?

[zebra]

all look exactly the same

light brown/orange tinge, no oil on the crowns

[SargeRX8]

Get one of these if you really want to have a look at the top of the piston and the walls in the cylinder.

http://www.supercheapauto.com.au/online-store/products/SCA-Inspection-Camera-3-5-LCD-Screen.aspx?pid=221633#Description

[Rolls]

A stuffed valve stem seal will cause it to burn oil, not sure if it will leak much/any compression though, anyone confirm?

Edited December 9, 2011 by Rolls

[zebra]

Should affect compression at all.

[DVS JEZ]

A worn guide can cause the valve to not seat correctly. A worn guide can cause the seal to leak also

[zebra]

ok back from the dead thread is no longer dead

Car died on me a couple of days ago, made a nice bang and stalled, but managed to get it going again so NFI what it was.

But just got back in from playing with it, popped the breather hose off and blocked the PCV...and Holy Shit cakes Batman, there be some blowby about lol

Has a nice chuff to it, so 1 or 2 clyinders are stuffed.

No idea why I'm updating this, but someone may care lol

[Marcus89]

Do you think it was related to the earlier issues or just bad luck that cause the motor to blow?